1. Field of the Invention
The present invention relates generally to methods and compositions useful for distinguishing neoplastic cells from normal cells. More particularly, the invention relates to the identification and preparation of polynucleotides and polypeptides useful in identifying the expression of a novel intestinal oncofetal gene in neoplastic cells.
With the advent of new and effective methods for cancer therapy, it has become increasingly important to be able to provide early diagnosis and to monitor the status of the cancer during the course of treatment. Many treatments, in order to be effective, must be commenced early in the course of the disease, and it is critical to monitor the tumor load during treatment in order to adjust the treatment regimen accordingly.
One approach to the diagnosis and monitoring of cancer is based on detecting the expression or presence of tumor antigens in biological specimens, particularly serum and tissue samples. Such tumor antigens, often referred to as tumor markers, are substances, typically proteins, glycoproteins, polysaccharides, and the like, which are produced by the tumor cells characteristic thereof. Often, the tumor marker may be produced by normal cells as well as tumor cells, but in the tumor cell the production has somehow become atypical. For example, production of the tumor marker may be greatly increased in the cancer cells, may be shed into circulation by the tumor cells, or the like.
Although a number of tumor markers have been identified in the past, no single tumor antigen has thus far provided an entirely reliable basis for cancer diagnosis and monitoring. Therefore, it is desirable to identify additional tumor markers which can be used singly or in combination with other tumor markers in the diagnosis and detection of cancer.
2. Description of the Background Art
Intestinal cell line IEC-18 was described by Quaroni and Isselbacher (1981) J. Natl. Cancer Inst. 67:1353-1362. This cell line was used in the preparation of the cDNA clone utilized to identify the novel intestinal oncofetal gene of the present invention.